Ruby 3.4 frozen string literals: What Rails developers need to know

bitbckt 7/9/2025|

Just a bit under 15 years after we did this at Twitter.

ksec 7/9/2025||

I would assume if Shopify and Github are on board then Rails is pretty well tested.

dorianmariecom 7/9/2025||

btw byroot in this thread is a ruby code committer and rails core committer as well

ksec 7/10/2025||

Many comments about Python 2-3 moves. The problem with Python was that 2 to 3 offers little to no incentive.

So I sometimes wonder why JIT isn't used as a motivation to move / remove features. Basically if you want JIT to work, your code has to be x ready or without feature x. So if you still want those performance improvements you will have to move forward.

phendrenad2 7/9/2025||

Has anyone actually benchmarked the use of frozen string literals? I feel like this is one of those micro-optimizations that everyone does, but they're probably accomplishing a diminishingly small performance improvement, while making the codebase less readable. On net, a negative.

byroot 7/9/2025|

Yes: https://bugs.ruby-lang.org/issues/20205#note-34

phendrenad2 7/10/2025||

Ah excellent. Seems like a modest performance improvement.

samgranieri 7/9/2025||

This should hopefully go over easier than the keywords arguments transition.

baggy_trough 7/9/2025||

I wonder what the basis is for the description of the 3.7 / 4 ruby releases is. I haven't seen this transition plan with version numbers described outside of this blog post.

MallocVoidstar 7/9/2025|

It's used as an example here: https://bugs.ruby-lang.org/issues/20205

But not actually stated it's the plan. I'd bet whatever LLM wrote the article took it as a stronger statement than it is.

prateekkish 7/9/2025||

Hey there. I wrote the article. While I know the version numbers aren’t concrete, I added the proposal anyways as a way for readers to visualise what the maintainers had in mind. Since we’re only at 3.4 with 3.5 in preview, it can’t be claimed concretely what the future holds. I just didn’t make that super obvious in the post.

I had to explain the same reasoning in Reddit the other day. Perhaps it’s time to take this as a feedback and update the blog.

Btw I just asked gpt to write an article on the same topic, with a reference to the Ruby issues page. And it DID NOT add the future proposal part. So LLMs are definitely smarter than me.